Polyamide and acrylic polymer coated glass fiber reinforcements, reinforced polymeric composites and a method of reinforcing a polymeric material

Abstract

The present invention provides a sized glass fiber strand adapted to reinforce a polymeric matrix material. The sizing composition includes a polyamide which is the reaction product of a polycarboxylic acid and a polyoxyalkylene amine; an acrylic polymer which is essentially free of epoxy functionality; a coupling agent and a fiber lubricant which is different from the polyamide, the sizing composition being essentially free of a urethane-containing polymer. Composites reinforced with the sized glass fiber strand and a method of reinforcing a composite are also provided.

Therefore, I claim: 
     
       1. A glass fiber strand adapted to reinforce a polymeric matrix material, the strand having thereon a sizing composition comprising: (a) a polyamide which is the reaction product of (1) a polycarboxylic acid and (2) a polyoxyalkylene amine;   (b) an acrylic polymer which is essentially free of epoxy functionality;   (c) a coupling agent selected from the group consisting of organo silane coupling agents, transition metal coupling agents, amino-containing Werner coupling agents and mixtures thereof; and   (d) a fiber lubricant which is different from the polyamide of (a), the sizing composition being essentially free of a urethane-containing polymer.   
     
     
       2. The glass fiber strand according to claim 1, wherein the sizing composition is present as a dried residue upon at least a portion of a surface of the strand. 
     
     
       3. The glass fiber strand according to claim 1, wherein the polycarboxylic acid of the polyamide (a) is a dicarboxylic acid. 
     
     
       4. The glass fiber strand according to claim 3, wherein the dicarboxylic acid is selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, itaconic acid, phthalic acid, malic acid and tartaric acid. 
     
     
       5. The glass fiber strand according to claim 1, wherein the polyoxyalkylene amine of the polyamide (a) is selected from the group consisting of triethylene glycol diamine, tetraethylene glycol diamine and polyoxypropylene diamines. 
     
     
       6. The glass fiber strand according to claim 1, wherein the polyamide comprises about 5 to about 95 weight percent of the sizing composition on a total solids basis. 
     
     
       7. The glass fiber strand according to claim 1, wherein the acrylic polymer of the sizing composition is prepared by vinyl addition polymerization of a monomer component comprising an acrylic monomer. 
     
     
       8. The glass fiber strand according to claim 6, wherein the acrylic monomer of the monomer component is selected from the group consisting of acrylic acid, methacrylic acid, alkyl esters of acrylic acid, alkyl esters of methacrylic acid, acrylic anhydrides, acrylamides, acrylonitriles, derivatives thereof and mixtures thereof. 
     
     
       9. The glass fiber strand according to claim 7, wherein the monomer component of the acrylic polymer further comprises a vinyl addition polymerizable monomer different from the acrylic monomer. 
     
     
       10. The glass fiber strand according to claim 9, wherein the vinyl addition polymerizable monomer is selected from the group consisting of vinyl aromatics, dienes, vinyl halides, vinyl acetates, amides, nitriles, pyrrolidones, olefins and mixtures thereof. 
     
     
       11. The glass fiber strand according to claim 1, wherein the acrylic polymer is a homopolymer of acrylic acid. 
     
     
       12. The glass fiber strand according to claim 11, wherein the acrylic acid polymer has at least one acid functional group which is neutralized with ammonium hydroxide. 
     
     
       13. The glass fiber strand according to claim 1, wherein the acrylic polymer comprises about 20 to about 80 weight percent of the sizing composition on a total solids basis. 
     
     
       14. The glass fiber strand according to claim 1, wherein the coupling agent is an amino organo silane coupling agent. 
     
     
       15. The glass fiber strand according to claim 1, wherein the fiber lubricant is a cationic fiber lubricant which is selected from the group consisting of amine salts of fatty acids, alkyl imidazoline derivatives, acid solubilized fatty acid amides and mixtures thereof. 
     
     
       16. The glass fiber strand according to claim 1, wherein the sizing composition is essentially free of an epoxy material. 
     
     
       17. The glass fiber strand according to claim 1, wherein the sizing composition further comprises a film-forming material different from the polyamide, acrylic polymer and the fiber lubricant.